Groundwater Trends Research Articles

Trends in Austrian groundwater – Climate or human impact?

Study regionAustria. Study focusUsing publicly available data for the main components of the hydrological cycle we use standardization to calculate countrywide and regional averages of groundwater levels, stream stages and precipitation. These averages get analyzed for the occurrence of trends, compared with each other and the Austrian water use over time. New hydrological insights for the regionIt is shown that groundwater levels trend downwards until the 1980s, from whereon they recover. Precipitation follows this track, but the downward trend is much less severe. River stages lack data for the downward trending period, but follow the upward trend too. The trend in groundwater is a reverse of the trends observed in water use and we hypothesize that the discrepancy between average precipitation and average groundwater pre 1980s could be caused by the increasing water use in this period, especially since Austrias water demands are mostly sourced from groundwater.

Integrated geospatial, geostatistical, and remote-sensing approach to estimate groundwater level in North-western India

The depletion of groundwater resources in Northwest India has been extensively studied. The top priority to meet the scarcity of water for irrigation, industrial and domestic purposes is supplemented by groundwater. Geostatistical modelling approach is considered to be beneficial tool for the assessment, evaluation, monitoring, and management of groundwater resources. This study is an attempt to analyze the spatio-temporal variability of groundwater level in semi-arid region of Panipat district, Haryana, India using kriging technique to fill the data gaps. Ordinary kriging was found optimal for the interpolation of groundwater levels. The results revealed that there was not much seasonal variation and also the groundwater flow direction remained almost constant in the study area during the assessment period. Spatial variability analysis showed significant variation in groundwater level and further depicted that the study area had undergone more or less decline in groundwater over the period of time. To validate the observations and results geo spatial and remote sensing techniques including normalised difference vegetation index and impervious surface relationships were worked out. It was further co-related with the rainfall data and the canal network existing in Panipat region. The integrated approach substantiated the observed results with the ground reality and helped in better understanding of the causes of declining groundwater trend in central part of Panipat.

Utilizing GRACE and GLDAS data for estimating groundwater storage variability over the Krishna Basin

Abstract. Groundwater is utilized intensively as a source of fresh water for irrigation and human needs. Hence, it is necessary to monitor groundwater storage for water security of the region in the future. The present study aims to evaluate the groundwater resource over the Krishna basin in South India. The basin comprises of 210 major and medium irrigation projects, which makes it important to evaluate the groundwater balance for a sustainable groundwater draft. This study evaluates the trend in groundwater anomaly derived from GRACE mascon product. Results indicate that the Krishna basin is subjected to a strong decline in groundwater at a rate of 0.34 cm per year. Further, the study explores the seasonality of precipitation and its effect on groundwater by adopting an entropy-based approach. Results indicate the combined effect of delay in precipitation to attain peak and reduced duration of the wet season as a primary reason for the decline in the groundwater storage. The result shows that the reduction in groundwater storage affects the evapotranspiration over the region.

Drivers, patterns and velocity of saltwater intrusion in a stressed aquifer of the East African coast: Joint analysis of groundwater and geophysical data in southern Kenya

Fresh groundwater resources in coastal East Africa are crucial for the region's socio-economic development but are under threat of salinization caused by changes in recharge patterns and increasing abstraction. With the aim of establishing the drivers behind saltwater intrusion and its current spatial extent, we studied the Kenyan South Coast aquifer, a representative, strategic aquifer under increased pressure. Investigations included electrical resistivity tomography (ERT) surveys and in-situ groundwater measurements (water table and basic quality) together with the analysis of available long-term climatic and borehole monitoring data. Over the last 40 years, groundwater electrical conductivity values at the well field increased by about three times and groundwater levels declined by 1–3 m over the last decade. When put in perspective with the long-term climate (rainfall, temperature) and abstraction records, these trends in groundwater appear to be primarily driven by increased borehole abstraction (+400 m3/day per year in average), whereas observed increasing temperature (+0.02 °C per year) and decreasing rainfall (−0.8 mm per year) could potentially act as a secondary control through reduced recharge. However the low statistical significance obtained for both rainfall and temperature trends over the observation period suggests that no clear conclusion can be made with regards to long-term climate impact on groundwater. Groundwater quality mapping showed that proximity to the ocean, presence of abstraction well-fields and regional geology control groundwater salinity patterns at regional scale. Locally, geophysical data showed that, saltwater intrusion spatial patterns are controlled by local aquifer lithology, groundwater abstraction and freshwater recharge in floodplains. Comparison with previous (1984) resistivity data showed that the saltwater front has advanced toward the well-field by up to 2 km and rose by up to 80 m over the last 30 years, which corresponds to a maximal velocity of about 60 m/y horizontally and 2 m/y vertically. Implementation of groundwater management strategies such as sustainable groundwater exploitation, sourced alternative water supply, and managed aquifer recharge are required to mitigate the effects of seawater intrusion along the East African coastal strip.

Scarcity of fresh water resources in the Ganges Delta of Bangladesh

Understanding the interdependency, availability, and accessibility of surface water and groundwater plays a major role in identifying and managing water security. The Ganges Delta in Bangladesh is a classic example of a water insecurity scenario in a transboundary river basin where concerns in quantity, quality, and timing of available water are producing disastrous conditions. This study examines surface water and groundwater uses and demands, seasonal availability, sustainability, and potential water security concerns. Human interventions that can influence seasonal water availability and shifting demands between surface water and groundwater are also examined. Surface water availability was analyzed using streamflow including the effects of upstream water diversions, rainfall, temperature, and evapotranspiration. Groundwater data was collected from 283 locations established by the Bangladesh Water Development Board. Total water storage anomaly data from the GRACE satellite (2002–2016) was analyzed to assess changes in groundwater availability. Both in situ and GRACE data show a significant declining trend in groundwater. Comparisons of groundwater recharge and withdrawal amounts in six different years (1983, 2009–2012, 2015) indicate an unsustainable water withdrawal condition. Irrigation is the largest sector of off-stream water use with total water withdrawal amounting to 31% for surface water and 68% for groundwater. The region’s domestic water use entirely depends on groundwater, which is problematic due to arsenic pollution. This study provides insight into the changes in surface water and groundwater resources and limitations to freshwater availability, thereby encouraging a better management strategy for water resources in the region.

Understanding the association between climate variability and the Nile's water level fluctuations and water storage changes during 1992–2016

With the construction of the largest dam in Africa, the Grand Ethiopian Renaissance Dam (GERD) along the Blue Nile, the Nile is back in the news. This, combined with Bujagali Dam on the White Nile are expected to bring ramification to the downstream countries. A comprehensive analysis of the Nile's waters (surface, soil moisture and groundwater) is, therefore, essential to inform its management. Owing to its shear size, however, obtaining in-situ data from “boots on the ground” is practically impossible, paving way to the use of satellite remotely sensed and models' products. The present study employs multi-mission satellites and surface models' products to provide, for the first time, a comprehensive analysis of the changes in Nile's stored waters' compartments; surface, soil moisture and groundwater, and their association to climate variability (El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD)) over the period 1992–2016. In this regard, remotely sensed altimetry data from TOPEX/Poseidon (T/P), Jason-1, and Jason-2 satellites along with the Gravity Recovery And Climate Experiment (GRACE) mission, and the Tropical Rainfall Measuring Mission Project (TRMM) rainfall products are applied to analyze the compartmental changes over the Nile River Basin (NRB). This is achieved through the creation of 62 virtual gauge stations distributed throughout the Nile River that generate water levels, which are used to compute surface water storage changes. Using GRACE total water storage (TWS), soil moisture data from multi-models based on the Triple Collocation Analysis (TCA) method, and altimetry derived surface water storage, Nile basin's groundwater variations are estimated. The impacts of climate variability on the compartmental changes are examined using TRMM precipitation and large-scale ocean-atmosphere ENSO and IOD indices. The results indicate a strong correlation between the river level variations and precipitation changes in the central part of the basin (0.77 on average) in comparison to the northern (0.64 on average) and southern parts (0.72 on average). Larger water storages and rainfall variations are observed in the Upper Nile in contrast to the Lower Nile. A negative groundwater trend is also found over the Lower Nile, which could be attributed to a significantly lower amount of rainfall in the last decade and extensive irrigation over the region.

Evaluation of groundwater discharge into surface water by using Radon-222 in the Source Area of the Yellow River, Qinghai-Tibet Plateau

Understanding hydrological processes in the Source Area of the Yellow River (SAYR), Qinghai-Tibet Plateau, is vital for protection and management of groundwater and surface water resources in the region. In situ water measurements of exchange rates between surface water and groundwater are, however, hard to conduct because of the harsh natural conditions of the SAYR. We here present an indirect method using in situ 222Rn measurements to estimate groundwater discharge into rivers and lakes in the SAYR. 222Rn was measured in rivers, lakes, groundwater and springs during three sampling periods (2014–2016), and the results indicate large variability in the concentration of the isotope. The data also indicate decreasing 222Rn trends in groundwater in the cold season (the Feb-2015 sampling period) which may be linked to frequency of capturing 222Rn in the frozen ground caused by geocryogenic processes. In addition, permafrost spatial extent and freeze-thaw processes have strongly affected the hydrological conditions in the region.

Seasonal and Decadal Groundwater Changes in African Sedimentary Aquifers Estimated Using GRACE Products and LSMs

Increased groundwater abstraction is important to the economic development of Africa and to achieving many of the Sustainable Development Goals. However, there is little information on long-term or seasonal groundwater trends due to a lack of in situ monitoring. Here, we used GRACE data from three products (the Centre for Space Research land solution (CSR), the Jet Propulsion Laboratory’s Global Mascon solution (JPL-MSCN), and the Centre National D’etudes Spatiales / Groupe de Recherches de Géodésie Spatiale solution (GRGS)), to examine terrestrial water storage (TWS) changes in 12 African sedimentary aquifers, to examine relationships between TWS and rainfall , and estimate groundwater storage (GWS) changes using four Land Surface Models (LSMs) (Community Land Model (CLM2.0), the Variable Infiltration Capacity model (VIC), the Mosaic model (MOSAIC) and the Noah model (NOAH)). We find that there are no substantial continuous long-term decreasing trends in groundwater storage from 2002 to 2016 in any of the African basins, however, consistent rising groundwater trends amounting to ~1 km3/year and 1.5 km3/year are identified in the Iullemmeden and Senegal basins, respectively, and longer term variations in ΔTWS in several basins associated with rainfall patterns. Discrete seasonal ΔTWS responses of ±1–5 cm/year are indicated by GRACE for each of the basins, with the exception of the Congo, North Kalahari, and Senegal basins, which display larger seasonal ΔTWS equivalent to approx. ±11–20 cm/year. The different seasonal responses in ΔTWS provide useful information about groundwater, including the identification of 5 to 9 month accumulation periods of rainfall in many semi-arid and arid basins as well as differences in ΔTWS responses between Sahelian and southern African aquifers to similar rainfall, likely reflecting differences in landcover. Seasonal ΔGWS estimated by combining GRACE ΔTWS with LSM outputs compare inconsistently to available in situ measurements of groundwater recharge from different basins, highlighting the need to further develop the representation of the recharge process in LSMs and the need for more in situ observations from piezometry.

Chronic groundwater decline: A multi-decadal analysis of groundwater trends under extreme climate cycles

Chronic groundwater decline is a concern in many of the world’s major agricultural areas. However, a general lack of accurate long-term in situ measurement of groundwater depth and analysis of trends prevents understanding of the dynamics of these systems at landscape scales. This is particularly worrying in the context of future climate uncertainties. This study examines long‐term groundwater responses to climate variability in a major agricultural production landscape in southern Queensland, Australia. Based on records for 381 groundwater bores, we used a modified Mann-Kendall non-parametric test and Sen’s slope estimator to determine groundwater trends across a 26-year period (1989–2015) and in distinct wet and dry climatic phases. Comparison of trends between climatic phases showed groundwater level recovery during wet phases was insufficient to offset the decline in groundwater level from the previous dry phase. Across the entire 26-year sampling period, groundwater bore levels (all bores) showed an overall significant declining trend (p < 0.05) of an average 0.06 m year−1. Fifty-one bores (20%) exhibited significant declining groundwater levels (p < 0.05), 25 bores (10%) exhibited significant rising groundwater levels (p < 0.05), and 175 bores (70%) exhibited no significant change in groundwater levels (p > 0.05). Spatially, both declining and rising bores were highly clustered. We conclude that over 1989–2015 there is a significant net decline in groundwater levels driven by a smaller subset of highly responsive bores in high irrigation areas within the catchment. Despite a number of targeted policy interventions, chronic groundwater decline remains evident in the catchment. We argue that this is likely to continue and to occur more widely under potential climate change and that policy makers, groundwater users and managers need to engage in planning to ensure the sustainability of this vital resource.

Improving the Reliability of Numerical Groundwater Modeling in a Data-Sparse Region

In data-sparse areas, due to the lack of hydrogeological data, numerical groundwater models have some uncertainties. In this paper, a nested model and a multi-index calibration method are used to improve the reliability of a numerical groundwater model in a data-sparse region, the Nalinggele River catchment in the Qaidam Basin. Referencing this key study area, a regional three-dimensional groundwater flow model is developed in a relatively complete hydrogeological unit. A complex set of calibration indices, including groundwater fitting errors, dynamic groundwater trends, spring discharges, overflow zone location, and groundwater budget status, are proposed to calibrate the regional numerical groundwater model in the Nalinggele alluvial–proluvial fan. Constrained by regional groundwater modeling results, a local-scale groundwater model is developed, and the hydrogeological parameters are investigated to improve modeling accuracy and reliability in this data-sparse region.

Regional-scale groundwater investigations for the Crossrail project

The Crossrail project includes a new underground railway through the heart of London. It will connect with 110 km of new or upgraded sections of surface rail to Reading, Shenfield and Abbey Wood. Ground investigations for the central tunnelled sections began during the 1990s and continued until 2011 according to a strategy that was based on a review of other major tunnelling projects and best practice. The level of detail in the investigations and subsequent groundwater monitoring varied according to local geological complexity and design requirements. A total of 1019 boreholes were drilled to a maximum depth of 114 m and contained a total of 1314 piezometers. Of these, 233 piezometers were installed during the 1990s and 1081 piezometers and several other monitoring types were installed in the following phase during the 2000s. The ground and groundwater investigation strategy included the following: (1) groundwater monitoring to accurately determine the multiple aquifer regional groundwater regime with varying underdrainage, in the west; (2) tidal monitoring in the east, where an unconfined single aquifer system predominated; (3) investigation of the impact of local features (e.g. fault zones and scour features); (4) determination of long-term groundwater trends. Crossrail data were supplemented with third-party data to provide more information on the far field and provide more definition on larger scale geological structures (e.g. faulting at Farringdon and Limmo). Installation trials were conducted on several types of installation, and their performance for monitoring multiple aquifers, in particular during permeability tests, is discussed. For large projects such as Crossrail, long-term performance of groundwater monitoring installations is critical for establishing a baseline in addition to obtaining information for design. Annual reviews of data backed up by remediation works allowed many installations to provide reliable groundwater data for up to a decade prior to the construction phase.

Nitrate trends in groundwater of the Campania region (southern Italy).

The Environmental Protection Agency of the Campania region in Italy (ARPAC) manages a groundwater quality monitoring network. For almost all the polluted waters, the key parameter driving the classification is the concentration of nitrate; hence, the Campania region, in coherence with the EU regulations, outlined the vulnerable areas and undertook remediation policies. The best groundwater quality is recorded for carbonate aquifers of the Apennine chain; on the contrary, the Tyrrhenian coastal plains are affected by severe contamination, with a locally very contaminated groundwater of the shallow and also the deeper aquifers. The study is especially focused on a large coastal plain of Campania region, where nitrate concentration sometimes exceeds 200mg/L. The study, based on almost 200 sampling points for the whole region during the period 2003-2015 (approx two samples per year), verified the effectiveness of the groundwater monitoring network, the present distribution of nitrate in groundwater, and the evolution of nitrate trends at different scales: regional, groundwater body, and single well, using spatial and time series statistical approaches. Significant variations in contamination evolution within the study area have been observed and the correlation with land use has been highlighted.

Groundwater-level trends in the U.S. glacial aquifer system, 1964–2013

The glacial aquifer system in the United States is a major source of water supply but previous work on historical groundwater trends across the system is lacking. Trends in annual minimum, mean, and maximum groundwater levels for 205 monitoring wells were analyzed across three regions of the system (East, Central, West Central) for four time periods: 1964–2013, 1974–2013, 1984–2013, and 1994–2013. Trends were computed separately for wells in the glacial aquifer system with low potential for human influence on groundwater levels and ones with high potential influence from activities such as groundwater pumping. Generally there were more wells with significantly increasing groundwater levels (levels closer to ground surface) than wells with significantly decreasing levels. The highest numbers of significant increases for all four time periods were with annual minimum and/or mean levels. There were many more wells with significant increases from 1964 to 2013 than from more recent periods, consistent with low precipitation in the 1960s. Overall there were low numbers of wells with significantly decreasing trends regardless of time period considered; the highest number of these were generally for annual minimum groundwater levels at wells with likely human influence. There were substantial differences in the number of wells with significant groundwater-level trends over time, depending on whether the historical time series are assumed to be independent, have short-term persistence, or have long-term persistence. Mean annual groundwater levels have significant lag-one-year autocorrelation at 26.0% of wells in the East region, 65.4% of wells in the Central region, and 100% of wells in the West Central region. Annual precipitation across the glacial aquifer system, on the other hand, has significant autocorrelation at only 5.5% of stations, about the percentage expected due to chance.

Impacts of land use change and groundwater management on long-term nitrate-nitrogen and chloride trends in groundwater of Jeju Island, Korea

Impacts of land use changes and groundwater management actions on groundwater quality were evaluated at the island scale with spatiotemporal trends of NO3-N and Cl concentrations in groundwater of Jeju Island, Korea. The temporal trends from 1993 to 2012 in the concentrations of NO3-N and Cl from more than 3900 wells were estimated using the Mann–Kendall trend test and Sen’s slope analysis and compared with the land use change trend for the period 1995–2009. The results indicate that the upward trends in NO3-N were associated with the expansion of agricultural lands, whereas Cl trends were considered to be affected by other factors in addition to the land use changes. In the mid-mountainous region, the deterioration in the groundwater quality by the both NO3-N and Cl was expected due to the continuous expansion of agricultural lands. In the lowland area, the NO3-N and Cl components showed different trends depending on the regions. In the eastern area, increasing trends in NO3-N were observed due to the development of new agricultural areas, while the Cl concentration was observed to decrease as a result of the regulation on groundwater extraction to reduce seawater intrusion. Our study highlights that a comprehensive interpretation of trends in NO3-N and Cl and land use changes for long-term periods can provide useful insights to prepare for suitable groundwater management plans in the whole island perspective.

Assessment of fluoride contamination in groundwater from Basara, Adilabad District, Telangana State, India

The major objective of this study was to locate the vulnerable areas in terms of fluoride contamination. A total of 34 groundwater samples were collected from major drinking water sources in rural areas of Basara, Telangana, and studied with reference to the distribution and hydrogeochemistry of fluoride. The geochemical trend of groundwater in the study area demonstrates that sodium is the dominant cation (Na+ > Ca2+ > Mg2+ > K+) and chloride is the dominant anion (Cl– > HCO3– > SO42– > CO32– > NO3– > F–). The fluoride concentration varied from 0.06 to 4.33 (1.13 ± 0.90) mg L−1 with the highest fluoride level at Karegaon village (4.33 mg L−1). Seven locations showed the presence of fluoride in excess of permissible levels.

Assessment of salinity hazard in existing water resources for irrigation and potentiality of conjunctive uses: a case report from Gopalganj District, Bangladesh

A total of 21 water samples were collected from surface water (ponds and river) and groundwater samples from shallow tube well (STW) and deep tube well (DTW) from Gopalganj Sadar Upazila to evaluate the salinity hazard and suitability for irrigation purposes. Both surface and groundwater of the study area maintained the trend of Cl− > SO4 2− > PO4 3−. The cation trend in both surface and groundwater of the study area was Na+ > K+ > Ca2+ > Mg2+ > Fe. Correlation matrices and principal component analysis (PCA) confirmed the stress of salinity from elevated electrical conductivity and total dissolved solids (TDS) with Na+, K+, Cl− and total hardness (TH) in relation to Ca2+, Mg2+, PO4 3− and SO4 2−. Salinity hazard classification and Wilcox diagram for irrigation water classification demonstrate that shallow tube wells containing low alkali and low sodium hazard are an excellent source of irrigation waters and fall under good to fair class of water (55 % samples). Higher TH, sodium adsorption ratio (SAR), soluble sodium percentage (SSP) and other important analysis indicated that most of the surface water and DTW were not suitable for irrigation. Therefore, the best irrigation water quality was from STW. Nevertheless, to sustainably and efficiently utilize the existing water resources, cyclic conjunctive uses of river water, STW and DTW as well as excavation of pond to store rainwater were suggested.

High-resolution monitoring of nutrients in groundwater and surface waters: process understanding, quantification of loads and concentrations, and management applications

Abstract. Four sessions on "Monitoring Strategies: temporal trends in groundwater and surface water quality and quantity" at the EGU conferences in 2012, 2013, 2014, and 2015 and a special issue of HESS form the background for this overview of the current state of high-resolution monitoring of nutrients. The overview includes a summary of technologies applied in high-frequency monitoring of nutrients in the special issue. Moreover, we present a new assessment of the objectives behind high-frequency monitoring as classified into three main groups: (i) improved understanding of the underlying hydrological, chemical, and biological processes (PU); (ii) quantification of true nutrient concentrations and loads (Q); and (iii) operational management, including evaluation of the effects of mitigation measures (M). The contributions in the special issue focus on the implementation of high-frequency monitoring within the broader context of policy making and management of water in Europe for support of EU directives such as the Water Framework Directive, the Groundwater Directive, and the Nitrates Directive. The overview presented enabled us to highlight the typical objectives encountered in the application of high-frequency monitoring and to reflect on future developments and research needs in this growing field of expertise.

A comparison of watershed storage trends over the eastern and upper Midwestern regions of the United States, 2003–2015

AbstractBasin‐scale groundwater storage trends calculated from long‐term streamflow records provide insight into the evolution of watershed behaviors. Our study presents the first spatially relevant validation of recession‐based trend approaches by comparing three independent storage trend estimates using GRACE‐derived groundwater storage, in situ groundwater elevation observations, and recession‐based approaches for the time period of 2003–2015. Results documented consistent agreement between spatially interpolated groundwater observation trends and recession‐based storage trends, while GRACE‐derived groundwater trends were found to exhibit variable, poor comparisons. A decreasing trend in watershed storage was identified in the southeastern U.S. while increasing trends were identified in the northeast and upper Midwest estimated from recession‐based approaches. Our recession‐based approach conducted using nested watershed streamflow records identified variable watershed storage trends at scales directly applicable for comparative hydrology studies and for assisting in watershed‐based water resources management decisions.

Community-based groundwater and ecosystem restoration in semi-arid north Rajasthan (3): Evidence from remote sensing

Community-based measures recharging groundwater in semi-arid India has historically underpinned rural socio-ecological resilience, though are declining through technological, policy and other changes. Nevertheless, exemplars of community action are achieving catchment regeneration, including in Alwar District (Rajasthan) since the mid-1980s. This study analysed satellite remote sensing (RS) data to detect trends in groundwater and linked ecosystem services. Data from Landsat satellite missions offered a long time series and free access, though data gaps in the LandSat archive prior to 1997 limited time series analysis. ISODATA (Iterative Self Organising Data Analysis Technique) was used to analyse land cover trends, detecting increasing vegetation cover but not river rejuvenation due to limited spatial and spectral resolution. Analyses of NDVI (Normalised Difference Vegetation Index) and MSI (Moisture Stress Index) were used to assess change in vegetation cover, vigour and moisture stress over time. Analytical outputs were equivocal, although inter-annual fluctuations were observed to follow antecedent rainfall as vegetation responded to rising soil moisture and groundwater. Despite these equivocal conclusions, the research strongly suggests that analysis of RS data with improved resolution can provide surrogate indicators of change in groundwater and associated ecosystem services, supporting formulation of flexible policies incorporating local action to regenerate socio-ecological systems.

Geoinformatics based groundwater potential assessment in hard rock terrain of Ranchi urban environment, Jharkhand state (India) using MCDM–AHP techniques

The study was conducted to delineate the groundwater potential (GWP) zones and to analyze groundwater trend in Ranchi Urban Agglomeration (RUA), Jharkhand. Groundwater level (GWL) and its fluctuations were analyzed estimated by using time series regression and employing sum of least square method. The groundwater potential (GWP) zones were delineated using various terrain characteristics and modeled using analytical hierarchical process (AHP) in geographic information system (GIS) environment. The high rate of built-up growth (39.0%) and population growth (32.6%) enhanced the pressure over existing groundwater resources during 2001–2010. The hard rock formations and increasing urbanization retarded groundwater recharge in the region. The study revealed that the central parts are largely covered by built-up land (7.35%) and have very low GWP and also faced severe water crisis. The northern (17%), south-western parts (13%), southern (8.07%) and eastern (9.61%) parts have high to very high GWP with less groundwater fluctuation and shallow GWL resembling suitable site for future built-up development in view of groundwater resource availability. The groundwater condition suggested site specific methods to recharge and replenish groundwater within the urban milieu.